From my experience, there are three main things to worry about when going through water: Air intake, exhaust, ane electric stuff.
If you get in water up to your air intake, you are screwed. Engines don't like breathing water for some reason.
If the water covers your exhaust, you want to keep the pressure coming out of the exhaust enough to keep the water out, so stay on the gas if possible. The gas pedal doesn't have to be to the floor...
The electric is a different issue, and sometimes you never know until you get into the water. The radio and other electronics inside the cab defeinately won't like water, but you can short out stuff in the engine too if you have some questionable/exposed wiring.
If you are worried about the carpet and seats and getting wet, I would suggest staying out of water past the bottom of the doors. Water building up and spashing against most door shouldn't be a problem unless there is a really bad fit at the doors. Keep moving and the water should flow around for the most part, most of the time the path of least resistance for the water won't be into your cab.
Those are just my observations from my experience driving in the military and personal jeep driving.